Washing or cleaning agents mostly contain fragrances which impart a pleasant odor to the agents. The fragrances mostly mask the odor of the other ingredients, creating a pleasant odor impression for the user.
In the washing agents sector in particular, fragrances (referred to synonymously also as perfumes) are important constituents of the composition, since in both the wet and the dry state the laundry should have a pleasant and where possible also a fresh scent. The fundamental problem underlying the use of fragrances is that they are more or less highly volatile compounds, yet a lasting fragrance effect is desired. In the case in particular of fragrances which provide the fresh and light notes of the perfume and which because of their high vapor pressure evaporate particularly quickly, the desired persistence of the fragrance impression is very difficult to achieve.
A delayed fragrance release can occur through for example the carrier-bound use of fragrances. A carrier-bound precursor form of a fragrance is also known as a pro-fragrance or fragrance storage substance. In this context international patent application WO2007/087977 discloses the use of 1-aza-3,7-dioxabicyclo[3.3.0]octane compounds as pro-fragrances for the delayed release of fragrance aldehydes and fragrance ketones by hydrolysis. An alternative possibility for the delayed release of fragrances is the use of photoactivatable substances as pro-fragrances. Exposure to sunlight or to another electromagnetic radiation source of a certain wavelength induces the breakage of a covalent bond in the pro-fragrance molecule, causing a fragrance to be released.
U.S. Pat. No. 6,949,680 discloses the use of certain phenyl or pyridyl ketones as photoactivatable substances which in the presence of light in a photochemical fragmentation release a terminal alkene as an active substance. Said active substance has for example a fragrance-imparting or antimicrobial activity, which is first delayed by the photochemically induced decomposition and is released over an extended period on a specific surface.
WO2009/118219 A1 describes certain ketones as photoactivatable substances which allow the delayed release of cyclic compounds having at least one cyclic double bond, in particular cyclic terpenes or cyclic terpenoids having at least one cyclic double bond.
WO2010/066486 A2 describes certain beta-hydroxyketones as photoactivatable substances which in the presence of light allow for a release of fragrance aldehydes (perfume aldehydes) and fragrance ketones (perfume ketones).
The object of the present invention was to provide further photoactivatable substances as pro-fragrances which allow for the delayed release of perfume ketones, in particular of damascone.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.